Sensor pattern for a tactile input device

ABSTRACT

A tactile sensor includes a plurality of first sensing elements that are arranged in a plurality of rows on a first layer and a plurality of second sensing elements that are vertically aligned in a plurality of columns on the first layer. The second sensing elements in each column are electrically connected together and each of the plurality of columns are separate conductors from one another. The plurality of second sensing elements include a plurality of vertical elements that form an interlocking pattern with the plurality of first sensing elements.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of, and claims priority to, U.S.patent application Ser. No. 13/709,931, filed Dec. 10, 2012, entitled“SENSOR PATTERN FOR A TACTILE INPUT DEVICE”, which, in turn, claimspriority to U.S. Provisional Application No. 61/709,388, filed Oct. 4,2012, titled “SENSOR PATTERN FOR A TACTILE INPUT DEVICE,” which ishereby incorporated by reference in its entirety.

TECHNICAL FIELD

This description relates to a sensor pattern for a tactile input device.

BACKGROUND

Some computing devices, such as laptop computers, include one or moreinput devices, such as a mouse, a keyboard, or a touchscreen. Variouscomputing devices include a trackpad or touchpad that can be used inplace of or in addition to a mouse to maneuver a curser on a computerscreen, or to trigger one or more functions of a computing device. Suchtrackpads or touchpads can be coupled to, or integrated within, thecomputing device.

A touchpad (also referred to herein interchangeably as a trackpad) is apointing device featuring a tactile sensor or sensor, which is aspecialized surface that can detect and translate the motion andposition of a user's fingers to a relative position on screen. Touchpadsare a feature of laptop computers or mobile devices, and are also usedas a substitute for a mouse, for example where desk space is scarce.Because they vary in size, they can also be found on personal digitalassistants and portable media players. Wired or wireless touchpads arealso available as accessories. It is desirable to have a sensor thataccurately detects and translates the motion and position of a user'sfingers or other touch implement to a relative position on screen.

SUMMARY

According to one general aspect, a tactile sensor includes a pluralityof first sensing elements that are arranged in a plurality of rows on afirst layer and a plurality of second sensing elements that arevertically aligned in a plurality of columns on the first layer. Thesecond sensing elements in each column are electrically connectedtogether and each of the plurality of columns are separate conductorsfrom one another. The plurality of second sensing elements include aplurality of vertical elements that form an interlocking pattern withthe plurality of first sensing elements.

Implementations may include one or more of the following features. Forexample, the plurality of first sensing elements may include a pluralityof vertical elements that form the interlocking pattern with theplurality of vertical elements of the plurality of second sensingelements. The vertical elements from the plurality of the first sensingelements may alternate with the vertical elements from the plurality ofthe second sensing elements. The plurality of vertical elements from theplurality of first sensing elements may define rectangular-shapedprojections that project vertically along a horizontal element. Theplurality of first sensing elements and the plurality of second sensingelements may be formed using copper etching. The tactile sensor mayinclude a controller having a plurality of inputs and a plurality ofoutputs, where the plurality of first sensing elements may be operablycoupled to the plurality of inputs of the controller and the pluralityof second sensing elements may be operably coupled to the plurality ofoutputs of the controller. The plurality of second sensing elements maybe electrically connected together on a second layer. The second sensingelements may be connected one to the other on the second layer to form acontinuous vertical sensing element. The plurality of first sensingelements may be electrically isolated from the plurality of secondsensing elements. Each of the plurality of first sensing elements mayform a continuous horizontal line and each column of the plurality ofsecond sensing elements may interface along each of the continuoushorizontal sensing elements.

In another general aspect, a tactile sensor includes a plurality offirst sensing elements that are arranged in a plurality of rows on afirst layer and a plurality of second sensing elements that arevertically aligned in a plurality of columns on the first layer. Thesecond sensing elements in each column are electrically connectedtogether and each of the plurality of columns are separate conductorsfrom one another. The plurality of first sensing elements include aplurality of vertical elements that form an interlocking pattern withthe plurality of second sensing elements.

Implementations may include one or more of the following features. Forexample, the plurality of vertical elements from the plurality of firstsensing elements may define rectangular-shaped projections that projectvertically along a horizontal element. The plurality of first sensingelements and the plurality of second sensing elements may be formedusing copper etching. The tactile sensor may include a controller havinga plurality of inputs and a plurality of outputs, where the plurality offirst sensing elements may be operably coupled to the plurality ofinputs of the controller and the plurality of second sensing elementsmay be operably coupled to the plurality of outputs of the controller.The plurality of second sensing elements may be electrically connectedtogether on a second layer. The plurality of first sensing elements maybe electrically isolated from the plurality of second sensing elements.

In another general aspect, a tactile sensor includes a plurality offirst sensing elements that are arranged in a plurality of rows on afirst layer, where the plurality of first sensing elements include ahorizontal segment from which a plurality of vertical elements project.The tactile sensor includes a plurality of second sensing elements thatare vertically aligned in a plurality of columns on the first layer,with the second sensing elements in each column being electricallyconnected together and each of the plurality of columns being separateconductors from one another. The plurality of second sensing elementsinclude a horizontal segment from which a plurality of vertical elementsproject.

Implementations may include one or more of the following features. Forexample, the vertical elements from the plurality of the first sensingelements may alternate with the vertical elements from the plurality ofthe second sensing elements. The horizontal segment of each of the firstsensing elements may be disposed on the tactile sensor from a first sideof the sensor to a second side of the sensor. The plurality of firstsensing elements and the plurality of second sensing elements may beformed using copper etching.

The details of one or more implementations are set forth in theaccompanying drawings and the description below. Other features will beapparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an exemplary block diagram of a computing device including atactile input device according to an exemplary implementation.

FIG. 1B is an exemplary block diagram of the tactile input device andrelated components according to an exemplary implementation.

FIG. 2 is an exemplary schematic of a sensor pattern according to anexemplary implementation.

FIG. 3 is an exemplary schematic of a sensing element according to anexemplary implementation.

FIG. 4 is an exemplary schematic of a sensing element according to anexemplary implementation.

FIG. 5 is a diagram showing example or representative computing devicesand associated elements that may be used to implement the systems andmethods of FIGS. 1-4.

DETAILED DESCRIPTION

A tactile input device for use with a computing device can be used tocommunicate with and control operations of the computing device. Thetactile input device may include, for example, a trackpad or a touchpad. The terms trackpad and touch pad may be used interchangeablythroughout this document to mean the same thing. The tactile inputdevice can be configured to be contacted by a user on a top surface ofthe tactile input device to trigger an electronic signal within thecomputing device. For example, a user can slide or move one or morefingers, or in some cases, knuckles or a portion of a hand, across thetop surface of the tactile input device to move a cursor visible on adisplay of the computing device. The tactile input device can alsoinclude a “scroll” function to allow the user to for example, scrollvertically or horizontally across the display. The scroll function maybe equivalent to rolling a wheel on a mouse, or typing “page up” or“page down” buttons on the keyboard. The user may actuate the scrollfunction by holding both fingers down on the tactile input device, andmoving one or both fingers in the horizontal or vertical direction. Thetactile input device may respond by recognizing the fingers as a scrollgesture, and provide a scroll gesture output to other components of thecomputing system.

The tactile input device can also include a “click” function to allowthe user to for example, click or select items on the display, or toactuate a right click function. Various tactile input devices describedherein can allow a user to actuate a click function by exerting orapplying a force on a top surface of the tactile input device at anylocation on the top surface. In some implementations, the tactile inputdevice may not have a specific sensor location that the user finds toactuate a click function. In other implementations, the tactile inputdevice may include a portion (e.g., a bottom third of a trackpad) thatthe user may depress (e.g., with a certain amount of pressure) toactuate a click function. The tactile input device can also travel aconsistent vertical distance and provide a consistent tactile responseto the user when the user clicks on any portion of the top surface ofthe tactile input device.

The tactile input device may include a sensor component that is used todetermine a position of items (a user's fingers or hand, a stylus, etc.)that touch the tactile input device by sensing changes in capacitancelevels on the tactile input device and providing resulting signalinformation to a controller. The sensor may include multiple sensingelements that are arranged in a sensor pattern (or pattern). The sensingelements may be conductors and the terms sensing elements, conductorsand conductor segments are used interchangeably throughout this documentto mean the same thing. The pattern arrangement of the sensing elementsmay provide a higher number of interfaces (or gaps or spaces) betweenthe sensing elements, thus providing a greater number of sensitive areason the tactile input device on which to determine finger positioning.The pattern arrangement of the sensing elements may provide an improvedtactile input device that is sensitive over more of the surface area andbetter able to determine finger placement and positioning.

As used herein, a reference to a top view in a figure refers to a viewas viewed by a user during use of the tactile input device. For example,a top view can refer to a view of the tactile input device as disposedwithin a computing device such that the user can contact the top surfaceof the tactile input device to initiate an action within the computingdevice.

FIG. 1A is a diagram of a computing device 100 including a tactile inputdevice 110 according to an exemplary implementation. Computing device100 includes a display portion 102 and a base portion 104. Displayportion 102 may include a display 120 that can be, for example, a liquidcrystal display (LCD), a light emitting diode (LED) display, or othertype of electronic visual display device. The base portion 104 caninclude, among other components, a tactile input device 110, a housing112, and a keyboard portion 130.

The tactile input device 110 can include a sensor (not shown) and a topsurface 118, configured to receive inputs (e.g., a touch, swipe, scroll,drag, click, hold, tap, combination of inputs, etc.) from a user. Thesensor can be activated when a user enters an input on the top surface118 of the tactile input device 110, and can communicate electronicsignals within the computing device 100. The sensor can be, for example,a flame-retardant class-4 (FR3) printed circuit board. Other components,such as a dome switch, adhesive sheets, and cables (not shown), may alsobe integrated in computing device 100 to process input by a user viatactile input device 110 or keyboard 130. Various elements shown in thedisplay 120 of the computing device 100 may be updated based on variousmovements of contacts on the tactile input device 110 or the keyboard130.

Tactile input devices, such as tactile input device 110, may be used inself-contained portable laptop computers such as device 100, and do notrequire a flat surface near the computer. The tactile input device 110may be positioned close to the keyboard 130. The tactile input device110 may only use very short finger movements to move a cursor across thedisplay 120. While advantageous, this also makes it difficult for a userto move his or her finger(s) across the surface 118 of the tactile inputdevice 110 in a completely horizontal or vertical direction. Tactileinput device functionality is also available for desktop computers inkeyboards with built-in touchpads, and in mobile devices, as describedin more detail below with respect to FIG. 5.

The components of the input devices (e.g., 110, 130) described here canbe formed with a variety of different materials such as plastic, metal,glass, ceramic, etc. used for such components. For example, the topsurface 118 and base member 104 can each be formed, at least in part,with an insulating material and/or conductive material such as astainless steel material, for example, SUS301 or SUS304.

Some tactile input devices have “hotspots,” which are locations on thetactile input device 110 used for functionality beyond a mouse. Sometactile input device drivers support tap zones, regions where a tap willexecute a function, for example, pausing a media player or launching anapplication. Certain tactile input devices 110 may use two-fingerdragging for scrolling. The tactile input devices and associated devicedriver software may interpret, for example, holding two fingers on thesurface 118 of the tactile input device 110, and moving one or both ofthe fingers in a horizontal or vertical direction, as scrolling. All ofthese functions may be implemented in tactile input device driversoftware or firmware, and these functions can be modified or disabled.

In some computing devices, such as computing device 100, the tactileinput device 110 may sense any number of fingers (such as up to five, ormore) simultaneously, providing more options for input, such as theability to bring up a menu by tapping two fingers, dragging two fingersfor scrolling, or gestures for zoom in or out or rotate. Additionally,although input device 110 is depicted as a rectangle, it will beappreciated that input device 110 could be formed in a different shape,such as a circle, a square, or other shape without departing from thescope of the techniques described here. The functionalities describedherein, such as scrolling or zooming, may be interpreted by a gesturelibrary as a single gesture.

FIG. 1B is a diagram of the tactile input device 110 and relatedcomponents according to an exemplary implementation. Tactile inputdevice 110 includes the surface 118, a sensor 152, a controller 154, abus 156, a kernel driver 158, and a gesture library 160.

The surface 118 may be configured to be contacted by a user to actuateand trigger an electrical response within the computing device 100. Thesurface 118 may, for example, be on top of the tactile input device 110and above the sensor 152, parallel and flush or nearly flush with othercomponents of the computing device 100 (shown in FIG. 1A), such as a topsurface of the housing 112 of the base portion 104. The surface 118 maybe operably coupled to the sensor 152. The sensor 152 can be activatedwhen a user enters an input (e.g., a touch, swipe, or a click), such asby applying pressure on the top surface 118 of the tactile input device110. The sensor 152 can be, for example, a flame-retardant class-4 (FR4)printed circuit board. The sensor 152 may be responsive to applicationsof pressure on the surface 118 and/or sensor 152, and may providesignals to a controller 154 indicating changes in resistance and/orcapacitance in the sensor 152 based on the applications of touch and/orpressure.

The sensor 152 may include one or more layers. Sensing elements may bearranged in a pattern on a top layer of the sensor 152. The sensingelements may be electrically independent from one another and/or one ormore of the sensing elements may be electrically coupled to one anotheron a same layer, on a different layer or on a combination of the samelayer and a different layer. The sensor 152 and the pattern arrangementof the sensing elements is described in more detail below with respectto FIGS. 2-4.

Controller 154 may be operably coupled to sensor 152. Controller 154 maybe an embedded microcontroller chip and may include, for example,read-only firmware. Controller 154 may include a single integratedcircuit containing a processor core, memory, and programmableinput/output peripherals. Bus 156 may be a PS/2, I2C, SPI, WSB, or otherbus. Bus 156 may be operably coupled to controller 154 and maycommunicate with kernel driver 158. Kernel driver 158 may includefirmware and may also include and/or communicate with gesture library160. Gesture library 160 may include executable code, data types,functions, and other files (such as JAVASCRIPT files) which may be usedto process input to tactile input device 110 (such as multitouchgestures). Gesture library 160, in combination with kernel driver 158,bus 156, controller 154, sensor 152, and surface 118, may be used toimplement various processes, such as the processes described herein.

The components of the tactile input device 110, and theirinterrelationships, as shown and described with respect to FIG. 1B, aremerely an example. Functionalities of the gesture library 160 may beperformed by the kernel driver 158 and/or controller 154, an operatingsystem or application. The functionalities may, for example, be storedand/or included on a non-transitory computer-readable storage mediumcomprising instructions stored thereon that, when executed by aprocessor or the controller 154 of the computing system 100, areconfigured to cause the computing system 100 to perform any combinationof the functionalities or processes described herein. Or, the tactileinput device 110 may be designed as an application specific integratedcircuit (ASIC) to perform the functions described herein.

Referring to FIG. 2, an exemplary implementation of the sensor 152 isillustrated. FIG. 2 illustrates multiple sensing elements 202 a and 202b that are arranged in rows on a first layer. The sensing elements 202 aand 202 b are electrical conductors that may extend horizontally fromone side 216 of the sensor 152 to the other side 218 of the sensor 152.The sensing elements 202 a and 202 b may be electrically isolated fromone another and not electrically connected to each other on any layer.

Although FIG. 2 illustrates two (2) rows of sensing elements 202 a and202 b, the sensor 152 may include more than two rows. It is to beunderstood that FIG. 2 is merely an illustration of multiple rows ofsensing elements and it is not meant to limit the rows of sensingelements to just those illustrated.

The sensing elements 202 a and 202 b may be implemented using conductivematerial. In one exemplary implementation, the sensing elements 202 aand 202 b may be implemented as copper conductors. For example, thesensing elements 202 a and 202 b may be formed on the sensor 152 usingcopper etching. A pattern in the shape of the sensing elements 202 a and202 b may be formed on the sensor 152 and copper etching may be used tofill in the pattern for the sensing elements 202 a and 202 b. Othertypes of conductive materials may be used to form the sensing elements202 a and 202 b.

The sensing element 202 a may be independent from the sensing element202 b in that the elements are separate from one another. In oneexemplary implementation, the sensing elements 202 a and 202 b may beidentical in shape and size. The sensing elements 202 a and 202 b mayaligned with one another or they may be offset, even if the shapes areidentical. In other exemplary implementations, the sensing elements 202a and 202 b may not be identical in shape and size.

The sensing elements 202 a and 202 b may include a continuous horizontalelement from which multiple vertical elements project on both sides ofthe horizontal element. Also referring to FIG. 3, an exemplary schematicof the sensing element 202 a is illustrated. The sensing element 202 amay include the continuous horizontal element 330 from which multiplevertical elements 335 a-335 n project. The vertical elements 335 a-335 nproject from both sides of the horizontal element 330. In otherexemplary implementations, the vertical elements 335 a-335 n may projectfrom only one side of the horizontal element 330 depending on theplacement of the sensing element 202 a within the sensor.

As illustrated in FIG. 3, the vertical elements 335 a-335 n may berectangular-shaped projections. The rectangular-shaped projections alsomay be referred to as finger-shaped projections. In one exemplaryimplementation, each of the rectangular-shaped projections may each bethe same size (e.g., the same width and the same length). In otherexemplary implementations, the rectangular-shaped projections may varyin size.

There may be a space (e.g., 340 a, 340 b, etc.) between the verticalelements 335 a-335 n. The space between the vertical elements may beconfigured to receive correspondingly-shaped projections from othersensing elements (e.g., 204 a-204 c, 206 a-206 c, 208 a-208 c and 210a-210 c) in the sensor 152. In this manner, the vertical elements 335a-335 n may form an interlocking pattern with the other sensing elementswithout actually touching the other sensing elements such that there isa gap or an interface between the vertical elements 335 a-335 n and theother sensing elements.

While FIG. 3 illustrates the vertical elements 335 a-335 n asrectangular-shaped, it is to be understood that the vertical elements335 a-335 n may be other shapes as well. In one exemplaryimplementation, the vertical elements 335 a-335 n may be rounded edgessuch that the vertical elements appear more finger-shaped. Other shapes(e.g., square-shape) are also possible.

Referring back to FIG. 2, the sensor 152 also includes multiple sensingelements 204 a-204 c, 206 a-206 c, 208 a-208 c and 210 a-210 c that arevertically aligned in columns on the same layer as the sensing elements202 a and 202 b. For example, the sensor 152 illustrates four (4)separate columns of vertically aligned sensing elements, where thesensing elements in the same column are electrically connected together.Each column of sensing elements is electrically isolated from the othercolumns of sensing elements. Each of the columns is arranged from a top220 of the sensor 152 to the bottom 222 of the sensor 152.

For example, a first column of sensing elements includes the sensingelements 204 a, 204 b and 204 c. The sensing elements 204 a, 204 b and204 c within the first column are electrically connected together. Inone implementation, the sensing elements 204 a, 204 b and 204 c may beelectrically connected together on a different layer using theconnectors 224 a-224 h. For instance, the connectors 224 a-224 h mayelectrically stitch the sensing elements together on a different layerto form a single, vertically aligned conductive segment. The firstcolumn of sensing elements 204 a, 204 b and 204 care electricallyisolated from the other columns of sensing elements and from the sensingelements 202 a and 202 b.

The second column of sensing elements includes the sensing elements 206a, 206 b and 206 c. The sensing elements 206 a, 206 b and 206 c withinthe second column are electrically connected together. In oneimplementation, the sensing elements 206 a, 206 b and 206 c may beelectrically connected together on a different layer using theconnectors 226 a-226 h. For instance, the connectors 226 a-226 h mayelectrically stitch the sensing elements together on a different layerto form a single, vertically aligned conductive segment. The secondcolumn of sensing elements 206 a, 206 b and 206 c are electricallyisolated from the other columns of sensing elements and from the sensingelements 202 a and 202 b.

The third column of sensing elements includes the sensing elements 208a, 208 b and 210 c. The sensing elements 208 a, 208 b and 208 c withinthe third column are electrically connected together. In oneimplementation, the sensing elements 208 a, 208 b and 208 c may beelectrically connected together on a different layer using theconnectors 228 a- 228 h. For instance, the connectors 228 a-228 h mayelectrically stitch the sensing elements together on a different layerto form a single, vertically aligned conductive segment. The thirdcolumn of sensing elements 208 a, 208 b and 208 c are electricallyisolated from the other columns of sensing elements and from the sensingelements 202 a and 202 b.

The fourth column of sensing elements includes the sensing elements 210a, 210 b and 210 c. The sensing elements 210 a, 210 b and 210 c withinthe fourth column are electrically connected together. In oneimplementation, the sensing elements 210 a, 210 b and 210 c may beelectrically connected together on a different layer using theconnectors 230 a-230 h. For instance, the connectors 230 a-230 h mayelectrically stitch the sensing elements together on a different layerto form a single, vertically aligned conductive segment. The fourthcolumn of sensing elements 210 a, 210 b and 210 c are electricallyisolated from the other columns of sensing elements and from the sensingelements 202 a and 202 b.

Although FIG. 2 illustrates four (4) columns of three sensing elements204 a-204 c, 206 a-206 c, 208 a-208 c and 210 a-210 c, the sensor 152may include more than four columns and/or more than three sensingelements in each column. It is to be understood that FIG. 2 is merely anillustration of multiple columns of multiple sensing elements and it isnot meant to limit the columns of sensing elements to just thoseillustrated.

The sensing elements 204 a-204 c, 206 a-206 c, 208 a-208 c and 210 a-210c may be implemented using conductive material. In one exemplaryimplementation, the sensing elements 204 a-204 c, 206 a-206 c, 208 a-208c and 210 a-210 c may be implemented as copper conductors. For example,the sensing elements 204 a-204 c, 206 a-206 c, 208 a-208 c and 210 a-210c may be formed on the sensor 152 using copper etching. A pattern in theshape of the sensing elements 204 a-204 c, 206 a-206 c, 208 a-208 c and210 a-210 c may be formed on the sensor 152 and copper etching may beused to fill in the pattern for the sensing elements 204 a-204 c, 206a-206 c, 208 a-208 c and 210 a-210 c. Other types of conductivematerials may be used to form the sensing elements 204 a-204 c, 206a-206 c, 208 a-208 c and 210 a-210 c. The conductive material used inthe sensing elements 204 a-204 c, 206 a-206 c, 208 a-208 c and 210 a-210c may be the same conductive material used in the sensing elements 202 aand 202 b.

The sensing elements 204 a-204 c, 206 a-206 c, 208 a-208 c and 210 a-210c may include a horizontal element with multiple vertical elementsprojecting from the horizontal element, where the projecting verticalelements form an interlocking pattern with the sensing elements 202 aand 202 b. Also referring to FIG. 4, an exemplary schematic of thesensing element 204 a is illustrated. The sensing element 204 a mayinclude a horizontal element 440 from which multiple vertical elements445 a-445 d project. In the example of sensing element 204 a, thevertical elements 445 a-445 d project from one side of the horizontalelement 440. In other vertically aligned sensing elements, such as, forexample sensing element 204 b, the vertical elements may project fromboth sides of the horizontal element.

In some implementations, the sensing elements may be flipped or rotatedto fit within the sensor and the pattern with the other sensingelements. For example, sensing element 204 c is the same shape as thesensing element 204 a, but it has been rotated and flipped to fit withinthe pattern of sensing elements.

As illustrated in FIG. 4, the vertical elements 445 a-445 d may berectangular-shaped projections. The rectangular-shaped projections alsomay be referred to as finger-shaped projections. In one exemplaryimplementation, each of the rectangular-shaped projections may each bethe same size (e.g., the same width and the same length). In otherexemplary implementations, the rectangular-shaped projections may varyin size.

There may be a space 450 a-450 c between the vertical elements 445 a-445d. The space 450 a-450 c between the vertical elements may be configuredto receive correspondingly-shaped projections from other sensingelements (e.g., 202 a and 202 b) in the sensor 152. In this manner, thevertical elements 445 a-445 d may form an interlocking pattern with theother sensing elements (e.g., 202 a and 202 b) without actually touchingthe other sensing elements such that there is a gap or an interfacebetween the vertical elements 445 a-445 d and the other sensing elements202 a and 202 b.

While FIG. 4 illustrates the vertical elements 445 a-445 d asrectangular-shaped, it is to be understood that the vertical elements445 a-445 d may be other shapes as well. In one exemplaryimplementation, the vertical elements 445 a-445 d may be rounded edgessuch that the vertical elements appear more finger-shaped. Other shapes(e.g., square-shape) are also possible.

Referring back to FIG. 2, the area between the sensing elements may forma gap or an interface such that a capacitive coupling is formed betweenthe sensing elements. At any point where one of the horizontal sensingelements 202 a and 202 b interface with a vertically aligned sensingelement 204 a-204 c, 206 a-206 c, 208 a-208 c and 210 a-210 c, acapacitive coupling may be formed. The sensor 152 is sensitive to anychanges in coupling along the interface between the sensing elements. Inthis manner, the coupling occurs in the area between the sensingelements and the gaps between the sensing elements form the sensitivearea, where the sensor 152 may detect a user's fingers.

The pattern formed by the sensing elements 202 a and 202 b and thesensing elements 204 a-204 c, 206 a-206 c, 208 a-208 c and 210 a-210 ccreates a large number of interfaces (i.e., a large area of interfaces),thus creating a large number of sensitive areas. The pattern formedenables a large surface area or a large cumulative length of thesensitive interface. Referring to FIGS. 3 and 4, the lines 360 and 460,respectively, that form the outline of the sensing elements 202 a and204 a, represent a gap or interface with other sensing elements whenpositioned in the sensor 152. The gap or interface may be about 0.2 mm.Other gap distances may be used depending on the positioning of thesensing elements in the sensor 152.

In one exemplary implementation, the sensing elements 202 a and 202 bmay be electrically coupled to an input side (or sense side) of thecontroller 154 of FIG. 1B. The sensing elements 204 a-204 c, 206 a-206c, 208 a-208 c and 210 a-210 c may be electrically coupled to an outputside (or drive side) of the controller 154 of FIG. 1B.

In operation, firmware on the controller 154 instructs the controller154 to output a signal on one of the columns of sensing elements (e.g.,204 a-204 c, 206 a-206 c, 208 a-208 c or 210 a-210 c). When the outputis being driven, the controller 154 samples all of the sensing elements202 a and 202 b tied to the input of the controller 154. The controllermay sample the sensing elements 202 a and 202 b in sequence or in apattern. After driving one column of sensing elements and sampling therows of sensing elements, the controller 154 activates and drives theanother column of sensing elements and samples each of the rows ofsensing elements. The controller 154 repeats this process with eachcolumn of sensing elements by activating and driving one column ofsensing elements at a time and sampling each of the rows of sensingelements.

When the controller 154 samples the sensing elements 202 a and 202 b, itmeasures a value and compares the measured value to a known baselinevalue. The baseline value may be measured at power up of the trackpad. Adifference between the measured value and the baseline value at aparticular location may be the result of some parasitic capacitance atthat location. In this manner, the capacitive coupling at the interfacebetween one of the sensing elements in a column and one of the sensingelements in a row changes in value over the baseline value when a fingeris placed on the trackpad at that location.

Based on the location at an interface of where the difference incapacitance occurs, the firmware in the controller 154 can determine anX-Y position and cause an appropriate action to occur such as, forexample, cursor movement on a display. A centroiding algorithm may takethe signals from the entire sensor 152, group the measurements fromdifferent sensing elements that are close to one another and then groupthem into a circle or an ellipse that represents the area of contact onthe trackpad.

The sensor pattern, including the shape and layout of the sensingelements and the interfaces between the sensing elements, provides animproved output signal to the controller 154 to enable the firmware onthe controller 154 to better differentiate between fingers placed on thetrackpad. The sensor pattern also reduces and/or eliminates loop backeffects (or re-radiation effect), where a charge is coupled from thesensor into the user's body and back into the sensor, which may causeareas of weak signals on the sensor and/or problems with the centroidingalgorithm. The capacitive coupling occurs along the interfaces betweenthe sensing elements and does not couple back into the user to cause aloop back effect. The sensor pattern is arranged to maximize the amountof sensitive area on the trackpad and to minimize the amount ofdeadspace in the sensing elements, where the sensor is not effective.

FIG. 5 is a block diagram showing example or representative computingdevices and associated elements that may be used to implement thesystems and methods of FIGS. 1-4. FIG. 5 shows an example of a genericcomputer device 500 and a generic mobile computer device 550, which maybe used with the techniques described here. Computing device 500 isintended to represent various forms of digital computers, such aslaptops, desktops, workstations, personal digital assistants, servers,blade servers, mainframes, and other appropriate computers. Computingdevice 550 is intended to represent various forms of mobile devices,such as personal digital assistants, cellular telephones, smart phones,and other similar computing devices. The components shown here, theirconnections and relationships, and their functions, are meant to beexemplary only, and are not meant to limit implementations of theinventions described and/or claimed in this document.

Computing device 500 includes a processor 502, memory 504, a storagedevice 506, a high-speed interface 508 connecting to memory 504 andhigh-speed expansion ports 510, and a low speed interface 512 connectingto low speed bus 514 and storage device 506. Each of the components 502,504, 506, 508, 510, and 512, are interconnected using various busses,and may be mounted on a common motherboard or in other manners asappropriate. The processor 502 can process instructions for executionwithin the computing device 500, including instructions stored in thememory 504 or on the storage device 506 to display graphical informationfor a GUI on an external input/output device, such as display 516coupled to high speed interface 508. In other implementations, multipleprocessors and/or multiple buses may be used, as appropriate, along withmultiple memories and types of memory. Also, multiple computing devices500 may be connected, with each device providing portions of thenecessary operations (e.g., as a server bank, a group of blade servers,or a multi-processor system).

The memory 504 stores information within the computing device 500. Inone implementation, the memory 504 is a volatile memory unit or units.In another implementation, the memory 504 is a non-volatile memory unitor units. The memory 504 may also be another form of computer-readablemedium, such as a magnetic or optical disk.

The storage device 506 is capable of providing mass storage for thecomputing device 500. In one implementation, the storage device 506 maybe or contain a computer-readable medium, such as a floppy disk device,a hard disk device, an optical disk device, or a tape device, a flashmemory or other similar solid state memory device, or an array ofdevices, including devices in a storage area network or otherconfigurations. A computer program product can be tangibly embodied inan information carrier. The computer program product may also containinstructions that, when executed, perform one or more methods, such asthose described above. The information carrier is a computer- ormachine-readable medium, such as the memory 504, the storage device 606,or memory on processor 502.

The high speed controller 508 manages bandwidth-intensive operations forthe computing device 500, while the low speed controller 512 manageslower bandwidth-intensive operations. Such allocation of functions isexemplary only. In one implementation, the high-speed controller 508 iscoupled to memory 504, display 516 (e.g., through a graphics processoror accelerator), and to high-speed expansion ports 510, which may acceptvarious expansion cards (not shown). In the implementation, low-speedcontroller 512 is coupled to storage device 506 and low-speed expansionport 514. The low-speed expansion port, which may include variouscommunication ports (e.g., USB, Bluetooth, Ethernet, wireless Ethernet)may be coupled to one or more input/output devices, such as a keyboard,a pointing device, a scanner, or a networking device such as a switch orrouter, e.g., through a network adapter.

The computing device 500 may be implemented in a number of differentforms, as shown in the figure. For example, it may be implemented as astandard server 520, or multiple times in a group of such servers. Itmay also be implemented as part of a rack server system 524. Inaddition, it may be implemented in a personal computer such as a laptopcomputer 522. Alternatively, components from computing device 500 may becombined with other components in a mobile device (not shown), such asdevice 550. Each of such devices may contain one or more of computingdevice 500, 550, and an entire system may be made up of multiplecomputing devices 500, 550 communicating with each other.

Computing device 550 includes a processor 552, memory 564, aninput/output device such as a display 554, a communication interface566, and a transceiver 568, among other components. The device 550 mayalso be provided with a storage device, such as a microdrive or otherdevice, to provide additional storage. Each of the components 550, 552,564, 554, 566, and 568, are interconnected using various buses, andseveral of the components may be mounted on a common motherboard or inother manners as appropriate.

The processor 552 can execute instructions within the computing device550, including instructions stored in the memory 564. The processor maybe implemented as a chipset of chips that include separate and multipleanalog and digital processors. The processor may provide, for example,for coordination of the other components of the device 550, such ascontrol of user interfaces, applications run by device 550, and wirelesscommunication by device 550.

Processor 552 may communicate with a user through control interface 558and display interface 556 coupled to a display 554. The display 554 maybe, for example, a TFT LCD (Thin-Film-Transistor Liquid Crystal Display)or an OLED (Organic Light Emitting Diode) display, or other appropriatedisplay technology. The display interface 556 may comprise appropriatecircuitry for driving the display 554 to present graphical and otherinformation to a user. The control interface 558 may receive commandsfrom a user and convert them for submission to the processor 552. Inaddition, an external interface 562 may be provide in communication withprocessor 552, so as to enable near area communication of device 550with other devices. External interface 562 may provide, for example, forwired communication in some implementations, or for wirelesscommunication in other implementations, and multiple interfaces may alsobe used.

The memory 564 stores information within the computing device 550. Thememory 564 can be implemented as one or more of a computer-readablemedium or media, a volatile memory unit or units, or a non-volatilememory unit or units. Expansion memory 574 may also be provided andconnected to device 550 through expansion interface 572, which mayinclude, for example, a SIMM (Single In Line Memory Module) cardinterface. Such expansion memory 574 may provide extra storage space fordevice 550, or may also store applications or other information fordevice 550. Specifically, expansion memory 574 may include instructionsto carry out or supplement the processes described above, and mayinclude secure information also. Thus, for example, expansion memory 574may be provide as a security module for device 550, and may beprogrammed with instructions that permit secure use of device 550. Inaddition, secure applications may be provided via the SIMM cards, alongwith additional information, such as placing identifying information onthe SIMM card in a non-hackable manner.

The memory may include, for example, flash memory and/or NVRAM memory,as discussed below. In one implementation, a computer program product istangibly embodied in an information carrier. The computer programproduct contains instructions that, when executed, perform one or moremethods, such as those described above. The information carrier is acomputer- or machine-readable medium, such as the memory 564, expansionmemory 574, or memory on processor 552, that may be received, forexample, over transceiver 568 or external interface 562.

Device 550 may communicate wirelessly through communication interface566, which may include digital signal processing circuitry wherenecessary. Communication interface 566 may provide for communicationsunder various modes or protocols, such as GSM voice calls, SMS, EMS, orMMS messaging, CDMA, TDMA, PDC, WCDMA, CDMA2000, or GPRS, among others.Such communication may occur, for example, through radio-frequencytransceiver 568. In addition, short-range communication may occur, suchas using a Bluetooth, WiFi, or other such transceiver (not shown). Inaddition, GPS (Global Positioning system) receiver module 570 mayprovide additional navigation- and location-related wireless data todevice 550, which may be used as appropriate by applications running ondevice 550.

Device 550 may also communicate audibly using audio codec 560, which mayreceive spoken information from a user and convert it to usable digitalinformation. Audio codec 560 may likewise generate audible sound for auser, such as through a speaker, e.g., in a handset of device 550. Suchsound may include sound from voice telephone calls, may include recordedsound (e.g., voice messages, music files, etc.) and may also includesound generated by applications operating on device 550.

The computing device 550 may be implemented in a number of differentforms, as shown in FIG. 5. For example, it may be implemented as acellular telephone 580. It may also be implemented as part of a smartphone 582, personal digital assistant, or other similar mobile device.

Implementations of the various techniques described herein may beimplemented in digital electronic circuitry, or in computer hardware,firmware, software, or in combinations of them. Implementations mayimplemented as a computer program product, i.e., a computer programtangibly embodied in an information carrier, e.g., in a machine-readablestorage device or in a propagated signal, for execution by, or tocontrol the operation of, data processing apparatus, e.g., aprogrammable processor, a computer, or multiple computers. A computerprogram, such as the computer program(s) described above, can be writtenin any form of programming language, including compiled or interpretedlanguages, and can be deployed in any form, including as a stand-aloneprogram or as a module, component, subroutine, or other unit suitablefor use in a computing environment. A computer program can be deployedto be executed on one computer or on multiple computers at one site ordistributed across multiple sites and interconnected by a communicationnetwork.

Method steps may be performed by one or more programmable processorsexecuting a computer program to perform functions by operating on inputdata and generating output. Method steps also may be performed by, andan apparatus may be implemented as, special purpose logic circuitry,e.g., an FPGA (field programmable gate array) or an ASIC(application-specific integrated circuit).

Processors suitable for the execution of a computer program include, byway of example, both general and special purpose microprocessors, andany one or more processors of any kind of digital computer. Generally, aprocessor will receive instructions and data from a read-only memory ora random access memory or both. Elements of a computer may include atleast one processor for executing instructions and one or more memorydevices for storing instructions and data. Generally, a computer alsomay include, or be operatively coupled to receive data from or transferdata to, or both, one or more mass storage devices for storing data,e.g., magnetic, magneto-optical disks, or optical disks. Informationcarriers suitable for embodying computer program instructions and datainclude all forms of non-volatile memory, including by way of examplesemiconductor memory devices, e.g., EPROM, EEPROM, and flash memorydevices; magnetic disks, e.g., internal hard disks or removable disks;magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor andthe memory may be supplemented by, or incorporated in special purposelogic circuitry.

To provide for interaction with a user, implementations may beimplemented on a computer having a display device, e.g., a cathode raytube (CRT) or liquid crystal display (LCD) monitor, for displayinginformation to the user and a keyboard and a pointing device, e.g., amouse or a trackball, by which the user can provide input to thecomputer. Other kinds of devices can be used to provide for interactionwith a user as well; for example, feedback provided to the user can beany form of sensory feedback, e.g., visual feedback, auditory feedback,or tactile feedback; and input from the user can be received in anyform, including acoustic, speech, or tactile input.

Implementations may be implemented in a computing system that includes aback-end component, e.g., as a data server, or that includes amiddleware component, e.g., an application server, or that includes afront-end component, e.g., a client computer having a graphical userinterface or a Web browser through which a user can interact with animplementation, or any combination of such back-end, middleware, orfront-end components. Components may be interconnected by any form ormedium of digital data communication, e.g., a communication network.Examples of communication networks include a local area network (LAN)and a wide area network (WAN), e.g., the Internet.

While certain features of the described implementations have beenillustrated as described herein, many modifications, substitutions,changes and equivalents will now occur to those skilled in the art. Itis, therefore, to be understood that the appended claims are intended tocover all such modifications and changes as fall within the true spiritof the embodiments of the invention.

What is claimed is:
 1. A tactile sensor comprising: a plurality of firstsensing elements that are arranged in a plurality of rows on a firstlayer; and a plurality of second sensing elements that are verticallyaligned in a plurality of columns on the first layer, with the secondsensing elements in each column being electrically connected togetherand each of the plurality of columns being separate conductors from oneanother, wherein the plurality of second sensing elements comprise aplurality of vertical elements that form an interlocking pattern withthe plurality of first sensing elements.
 2. The tactile sensor of claim1 wherein the plurality of first sensing elements comprise a pluralityof vertical elements that form the interlocking pattern with theplurality of vertical elements of the plurality of second sensingelements.
 3. The tactile sensor of claim 2 wherein the vertical elementsfrom the plurality of the first sensing elements alternate with thevertical elements from the plurality of the second sensing elements. 4.The tactile sensor of claim 2 wherein the plurality of vertical elementsfrom the plurality of first sensing elements define rectangular-shapedprojections that project vertically along a horizontal element.
 5. Thetactile sensor of claim 1 wherein the plurality of first sensingelements and the plurality of second sensing elements are formed usingcopper etching.
 6. The tactile sensor of claim 1 further comprising acontroller having a plurality of inputs and a plurality of outputs,wherein the plurality of first sensing elements are operably coupled tothe plurality of inputs of the controller and the plurality of secondsensing elements are operably coupled to the plurality of outputs of thecontroller.
 7. The tactile sensor of claim 1 wherein the plurality ofsecond sensing elements are electrically connected together on a secondlayer.
 8. The tactile sensor of claim 7 wherein the second sensingelements are connected one to the other on the second layer to form acontinuous vertical sensing element.
 9. The tactile sensor of claim 1wherein the plurality of first sensing elements are electricallyisolated from the plurality of second sensing elements.
 10. The tactilesensor of claim 1 wherein each of the plurality of first sensingelements forms a continuous horizontal line and each column of theplurality of second sensing elements interfaces along each of thecontinuous horizontal sensing elements.
 11. A tactile sensor comprising:a plurality of first sensing elements that are arranged in a pluralityof rows on a first layer; and a plurality of second sensing elementsthat are vertically aligned in a plurality of columns on the firstlayer, with the second sensing elements in each column beingelectrically connected together and each of the plurality of columnsbeing separate conductors from one another, wherein the plurality offirst sensing elements comprise a plurality of vertical elements thatform an interlocking pattern with the plurality of second sensingelements.
 12. The tactile sensor of claim 11 wherein the plurality ofvertical elements from the plurality of first sensing elements definerectangular-shaped projections that project vertically along ahorizontal element.
 13. The tactile sensor of claim 11 wherein theplurality of first sensing elements and the plurality of second sensingelements are formed using copper etching.
 14. The tactile sensor ofclaim 11 further comprising a controller having a plurality of inputsand a plurality of outputs, wherein the plurality of first sensingelements are operably coupled to the plurality of inputs of thecontroller and the plurality of second sensing elements are operablycoupled to the plurality of outputs of the controller.
 15. The tactilesensor of claim 11 wherein the plurality of second sensing elements areelectrically connected together on a second layer.
 16. The tactilesensor of claim 11 wherein the plurality of first sensing elements areelectrically isolated from the plurality of second sensing elements. 17.A tactile sensor comprising: a plurality of first sensing elements thatare arranged in a plurality of rows on a first layer, wherein theplurality of first sensing elements comprise a horizontal segment fromwhich a plurality of vertical elements project; and a plurality ofsecond sensing elements that are vertically aligned in a plurality ofcolumns on the first layer, with the second sensing elements in eachcolumn being electrically connected together and each of the pluralityof columns being separate conductors from one another, wherein theplurality of second sensing elements comprise a horizontal segment fromwhich a plurality of vertical elements project.
 18. The tactile sensorof claim 17 wherein the vertical elements from the plurality of thefirst sensing elements alternate with the vertical elements from theplurality of the second sensing elements.
 19. The tactile sensor ofclaim 17 wherein the horizontal segment of each of the first sensingelements is disposed on the tactile sensor from a first side of thesensor to a second side of the sensor.
 20. The tactile sensor of claim17 wherein the plurality of first sensing elements and the plurality ofsecond sensing elements are formed using copper etching.